CaniNectar Research

Independent Research Review: What Does the Wider Literature Say About Digestion and the Canine Microbiome?

Independent canine research consistently shows that diet composition, digestibility and nutrient availability can alter the gut microbiome and its metabolic environment. Evidence for routine digestive enzyme supplementation in healthy dogs is more limited, but studies support the broader principle that upstream digestion influences what reaches microbial communities further along the gut.

Open access

Independent Research Review: What Does the Wider Literature Say About Digestion and the Canine Microbiome?

Year

2026

Study type

Literature review explainer

Measured

Digestibility, nutrient availability, faecal microbiome composition and microbial metabolites

The research question

CaniNectar research is built around an upstream idea:

What happens during digestion changes what eventually reaches the gut microbiome.

That principle should not depend on CaniNectar studies alone.

So what does the wider, independent canine literature show?

Three questions are especially relevant:

Does diet and digestibility change the canine microbiome?

Is microbial composition linked with how nutrients are digested?

What evidence exists for adding digestive enzymes to the diets of dogs?

The answer is nuanced.

Independent research strongly supports the relationship between diet, nutrient digestion and the canine gut microbiome.

Evidence for routine enzyme supplementation in otherwise healthy dogs is much less developed.

What did they measure?

This article reviews independent canine studies addressing several connected areas.

Diet and microbiome composition

Studies comparing different diets can show whether changing the nutrients entering the digestive system alters microbial communities.

Digestibility

Researchers can measure how much protein, fat, carbohydrate and energy disappear from the gastrointestinal tract rather than being excreted.

Faecal microbiome analysis

16S sequencing and related techniques allow researchers to compare the relative abundance of bacterial groups between diets or interventions.

Metabolites

Some studies also examine compounds produced or altered within the gut, adding information about microbial activity rather than composition alone.

Digestive enzyme supplementation

A smaller body of canine research has examined whether adding external digestive enzymes changes nutrient digestibility or the faecal microbiome.

The studies do not all ask the same question, so their findings should not be treated as if they were one single experiment.

What was observed?

The wider literature supports several important conclusions.

Diet has a strong effect on the canine microbiome

Independent reviews consistently describe the canine gut microbiome as highly responsive to nutrient composition.

Changes in fibre, starch and protein can produce rapid changes in microbial communities.

A 2021 review by Pilla and Suchodolski describes the gut microbiome as metabolically responsive to the nutrient composition of the diet.

Digestibility and microbiome composition are connected

Controlled feeding studies have shown that diets differing in digestibility can also produce markedly different faecal microbiomes.

In one study of 12 dogs, fresh and human-grade diets were more digestible than an extruded diet and produced substantially less faecal output.

The same diets also altered the relative abundance of numerous bacterial genera.

This does not prove that greater digestibility is always better, but it demonstrates that nutrient processing and microbial composition are linked.

Microbial groups correlate with nutrient digestion

Research comparing different canine diets has found relationships between bacterial families and apparent protein and energy digestibility.

That reinforces the idea that digestion and microbiology cannot be considered completely independently.

Digestive enzyme supplementation in healthy dogs has mixed evidence

A controlled study in 14 healthy adult dogs examined plant-derived and animal-derived digestive enzyme supplements.

At manufacturer-recommended amounts, the supplements did not produce a broad improvement in macronutrient or energy digestibility.

This is an important finding.

Healthy dogs already produce substantial quantities of their own digestive enzymes, so external enzyme supplementation should not automatically be assumed to improve overall digestibility.

Other enzyme studies have found microbiome changes

A separate study in 11 healthy client-owned dogs found changes in the faecal microbiome when digestive enzyme and probiotic/enzyme preparations were introduced.

The relative abundance of several bacterial groups changed during the intervention.

However, because the later phase combined probiotics with digestive enzymes, the contribution of the enzyme component cannot be isolated cleanly.

Enzyme replacement is well established when endogenous enzyme production fails

In dogs with exocrine pancreatic insufficiency, pancreatic enzyme replacement is an established nutritional intervention.

That is a very different biological situation from supplementation in healthy dogs, but it clearly demonstrates how strongly digestive enzyme availability can influence nutrient digestion and the intestinal environment.

What does this study tell us?

The independent literature supports the broad biological framework behind the Science Hub:

Diet → Digestion → Substrate → Microbiome

What a dog eats influences digestion.

Digestion determines which nutrients are absorbed and which remain available further down the gastrointestinal tract.

Those remaining substrates help shape microbial composition and microbial metabolism.

That relationship is supported independently of CaniNectar.

The more specific question of whether adding digestive enzymes benefits healthy dogs is less settled.

Existing studies have used different enzyme sources, formulations, doses and endpoints, and the results are not uniform.

This distinction matters.

The strongest conclusion from the wider literature is not that every dog needs supplemental enzymes.

It is that upstream digestion and downstream microbiome biology are closely connected.

That is the scientific principle against which more specific nutritional interventions should be tested.

For direct canine data on Enzyme Rich Malt Extract, read the peer-reviewed microbiome and metabolome study.

What doesn't this study tell us?

The independent evidence has several limitations.

Different interventions

Studies use different diets, enzyme sources, formulations and feeding protocols.

Results from one preparation cannot automatically be transferred to another.

Healthy dogs versus dogs with digestive disease

Evidence from dogs with exocrine pancreatic insufficiency demonstrates the importance of digestive enzymes but should not be extrapolated directly to healthy dogs.

Small studies

Many canine nutrition studies involve relatively small numbers of animals.

Faecal microbiome measurements

Faecal samples mainly represent the end of the gastrointestinal tract and cannot show everything occurring in the stomach or small intestine.

Composition does not equal function

A change in bacterial abundance does not automatically indicate whether the change is beneficial, harmful or biologically important.

Limited direct enzyme research

There are comparatively few well-controlled studies examining digestive-enzyme supplementation in healthy dogs.

The appropriate conclusion is therefore one of biological plausibility and active research, not certainty.

Original research

Study details

Reference

Pilla R, Suchodolski JS. The Gut Microbiome of Dogs and Cats, and the Influence of Diet. Veterinary Clinics of North America: Small Animal Practice. 2021;51(3):605–621.

Oba PM, Utterback PL, Parsons CM, de Godoy MRC, Swanson KS. Nutrient digestibility and fecal characteristics, microbiota, and metabolites in dogs fed human-grade foods. Journal of Animal Science. 2021;99(2).

Sandri M, Dal Monego S, Conte G, Sgorlon S, Stefanon B. Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs. BMC Veterinary Research. 2017.

Komiya T, Seki S, Sako T. Effects of a digestive enzyme versus a commercially available probiotic/digestive enzyme preparation on the fecal microbiomes of healthy, client-owned dogs. Journal of Pet Animal Nutrition. 2022;25(2):71–79.

Twomey LN, Pethick DW, Rowe JB, et al. Effect of enzyme supplements on macronutrient digestibility by healthy adult dogs. British Journal of Nutrition. 2017.

Parambeth JC, Suchodolski JS, Steiner JM. Randomized placebo controlled clinical trial of an enteric coated micro-pelleted formulation of a pancreatic enzyme supplement in dogs with exocrine pancreatic insufficiency. Journal of Veterinary Internal Medicine. 2018;32(5):1591–1599.

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